1. The Field of the Invention
The present invention relates generally to expandable starch-based compositions. More particularly, the present invention relates to expandable fiber-reinforced starch-based compositions used to manufacture molded articles, methods of manufacturing such compositions, and methods of making fiber-reinforced articles therefrom.
2. The Relevant Technology
Many articles in commerce are designed and produced to be disposable after a single use. The most common materials in single-use articles are exemplified by paper, paperboard, plastics, polystyrenes, and metals. In part, the disposability of an item after a single use results from busy lifestyles that require instant or ready-made food and beverage containers. For example, one visit to a fast-food restaurant or convenience store can result in a single person using and discarding multiple disposable containers, some of which were only in use for less than five minutes or the time it takes to transport food from a grill to a serving tray. While these articles are typically disposed of after a single use, or after the primary product has been removed from the article in the form of a container, more often than not the articles are not biodegradable. Due to the overwhelming magnitude of the non-biodegradable, single-use articles being produced and distributed, the final destinations of such articles (e.g., landfills) are quickly becoming oversaturated, incapable, and/or insufficient for properly dealing with and/or destroying these articles.
As stated, one highly used material for the production of single-use items is polystyrene or polystyrene foams. Polystyrene foams and the articles manufactured therefrom are produced from expandable polystyrene (EPS), which are molded into the desired articles or shapes. More particularly, EPS compositions containing a gas or volatile solvent are prepared and expanded by heating so that it increases in volume and decreases in density. EPS compositions expand at ambient pressure until they fill the voids in the mold.
In response to the environmental problems associated with single-use and disposable articles, research has been conducted to find substitute materials that are biodegradable and environmentally friendly. Heretofore, the materials presented as substitutes for paper, paperboard, plastics, polystyrenes, and metals have heretofore exhibited inadequate mechanical properties. As such, a reasonable biodegradable material with sufficient strength characteristics has yet to be produced for being substituted for EPS materials. Thus, there remains a need for a strong biodegradable substitute for EPS compositions and EPS-based products.
Therefore, it would be advantageous to provide a strong biodegradable material that can be substituted for environmentally unfriendly materials. More particularly, it would be advantageous to mechanically reinforce a biodegradable material so as to provide a suitable replacement for EPS beads, sheets, and products.